Chromakeying vs Masking

Donald Blake · January 17th, 2009, 04:14 PM

Douglas here's the new VEG files with the added JPG but the problem dosent show with a still, curiously the outlined mask shows only with a video. I can send it to you by e-mail it's only 2.7megs.

Edward Troxel · January 17th, 2009, 08:32 PM

Move the Chroma Keyer FIRST in the chain. Or the Chroma Blur first and Chroma Keyer second. Put all the other effects AFTER those two. I did that on your original VEG file and the things that you're seeing totally went away.

Now... you still have the issue of black showing up above her head and below her legs but that's related to where the mask is located. However, just moving those two effects in the chain of effects clears it right up.

Donald Blake · January 18th, 2009, 02:06 AM

Ok so Edward figured it out!

The chromakey should always be first I guess, It was the Brithness and contrast effect that was outlining the mask.

It added some kinda shadowing around the women, I just adjusted the low threshold to 0.30 in the chromakeyer and voila.

Thanks Edward!

Donald Blake · January 18th, 2009, 11:49 AM

I did another test (see JPG) there was no chromakeying involved in this one, I copyed my original video file on to another track (track 1 & track 2 identical) deleted the chromakey and blur effect just for this test, I kept the brightness and contrast + color corrector + sharpen effects on both tracks at exactly the same settings, then I masked only the first track (without any shadowing), we can still see the masking outline, even if you change the order of the effects, the problem was fixed when I deleted all the effects.

So my conclusion to all this is that you have 2 options, 1- when masking you should never add any effects 2- render a file of the masking part without any effects then add it to the timeline and finally add the effects.

Wich to me seems like a major Vegas bug don't you think? by doing that I'd loose time and quality, what I don't understand is why nobody ever talked about this earlyer on this forum?

Douglas Spotted Eagle · January 18th, 2009, 12:38 PM

I did tell you to make sure that Blur/Keying are first. FX are ALWAYS added after a mask or key, regardless of what application you're using. Otherwise, you're asking the mask or key to process the FX, too. That's very hard to do. Color correction, FX, levels...all come after the key, never before. Chromablur and key first in chain (pre) and everything else comes after (post).
Whether it's Vegas, AE, MC, Premiere...It's all the same.
BTW, try to avoid brightness/contrast on video. Use Curves instead. B/C works on the chroma and luma, curves works on Luma and doesn't raise the apparent noise as much.

Michael Hutson · January 18th, 2009, 01:12 PM

Thanks for sharing your expertise, Douglas.

Donald Blake · January 18th, 2009, 07:57 PM

Quote:

Originally Posted by Douglas Spotted Eagle

...you'll need to set the key first...

haha sorry Douglas! I just noticed it.

Thanks for the great advice Douglas, if I use the Curves FX instead of Brithness & Contrast will my mask outline show? (like the JPG in my last post)

Edward Troxel · January 19th, 2009, 08:20 AM

As was said, place curves AFTER the key.

I agree that Brightness and Contrast really is NOT what you want to use. The other effects to a much better job. There's an entire discussion on Brightness and Contrast in another thread here from not too long ago. Here it is:
http://www.dvinfo.net/conf/what-happ...o-lighter.html

January 17th, 2009, 08:32 PM	#17
Edward Troxel Sponsor: JET DV Join Date: Dec 2001 Location: Southern Illinois Posts: 7,953	Move the Chroma Keyer FIRST in the chain. Or the Chroma Blur first and Chroma Keyer second. Put all the other effects AFTER those two. I did that on your original VEG file and the things that you're seeing totally went away. Now... you still have the issue of black showing up above her head and below her legs but that's related to where the mask is located. However, just moving those two effects in the chain of effects clears it right up. __________________ Edward Troxel [SCVU] JETDV Scripts/Scripting Tutorials/Excalibur/Montage Magic/Newsletters

January 18th, 2009, 11:49 AM	#19
Donald Blake Regular Crew Join Date: Dec 2006 Location: Montreal, Canada Posts: 142	I did another test (see JPG) there was no chromakeying involved in this one, I copyed my original video file on to another track (track 1 & track 2 identical) deleted the chromakey and blur effect just for this test, I kept the brightness and contrast + color corrector + sharpen effects on both tracks at exactly the same settings, then I masked only the first track (without any shadowing), we can still see the masking outline, even if you change the order of the effects, the problem was fixed when I deleted all the effects. So my conclusion to all this is that you have 2 options, 1- when masking you should never add any effects 2- render a file of the masking part without any effects then add it to the timeline and finally add the effects. Wich to me seems like a major Vegas bug don't you think? by doing that I'd loose time and quality, what I don't understand is why nobody ever talked about this earlyer on this forum? Attached Thumbnails

January 18th, 2009, 12:38 PM	#20
Douglas Spotted Eagle VASST Join Date: Jan 2004 Location: Stockton, UT Posts: 5,648	I did tell you to make sure that Blur/Keying are first. FX are ALWAYS added after a mask or key, regardless of what application you're using. Otherwise, you're asking the mask or key to process the FX, too. That's very hard to do. Color correction, FX, levels...all come after the key, never before. Chromablur and key first in chain (pre) and everything else comes after (post). Whether it's Vegas, AE, MC, Premiere...It's all the same. BTW, try to avoid brightness/contrast on video. Use Curves instead. B/C works on the chroma and luma, curves works on Luma and doesn't raise the apparent noise as much. __________________ Douglas Spotted Eagle/Spot Author, producer, composer Certified Sony Vegas Trainer http://www.vasst.com

January 18th, 2009, 01:12 PM	#21
Michael Hutson Major Player Join Date: Nov 2008 Location: Elgin, IL Posts: 249	Thanks Douglas Thanks for sharing your expertise, Douglas.

January 19th, 2009, 08:20 AM	#23
Edward Troxel Sponsor: JET DV Join Date: Dec 2001 Location: Southern Illinois Posts: 7,953	As was said, place curves AFTER the key. I agree that Brightness and Contrast really is NOT what you want to use. The other effects to a much better job. There's an entire discussion on Brightness and Contrast in another thread here from not too long ago. Here it is: http://www.dvinfo.net/conf/what-happ...o-lighter.html __________________ Edward Troxel [SCVU] JETDV Scripts/Scripting Tutorials/Excalibur/Montage Magic/Newsletters

January 18th, 2009, 02:06 AM	#18
Donald Blake Regular Crew Join Date: Dec 2006 Location: Montreal, Canada Posts: 142	Ok so Edward figured it out! The chromakey should always be first I guess, It was the Brithness and contrast effect that was outlining the mask. It added some kinda shadowing around the women, I just adjusted the low threshold to 0.30 in the chromakeyer and voila. Thanks Edward!